Composition for use in laundering



Patented Jan. 1, 1935 PATENT OFFICE COMPOSITION FOR. USE IN LAUNDERING Silas M. Ratzkofl, Philadelphia, Pa., assignorto Publicker Research and Development Company, Philadelphia, Pa., a corporation of, Pennsylno Drawing. Application July so, 1932,

Serial No. 627,107

BClilims.

My invention relates to the art of cleansing fabrics and more particularly to the neutralization and removal of alkaline substances and soaps in the course of laundering operations.

My process is primarily concerned with the laundering-step which is commonly considered under the designation ofsouring" and in connection with which in the prior practice it has been customary to use free acids, such, for example, as oxalic acid and acetic acid. In lieu of oxalic acid or acetic acid, acid salts havealso been The use of acids or acid salts, while functioning to neutralize the alkaline content in the fabrics, is nevertheless undesirable because of the fact that such materials injure the fabrics. This is especially so due to the fact that: is impossible to add just the precise amount of acid or acid salt required to just neutralize the alkaline constituents present. Furthermore, such or acid salts cause a stiff-:-

fening and consequqlweakening of the fabric with the result thatz fthe life of the fabric is greatly reduced by .such laundering agents. Further, in connection with such souring treatments, discoloration or staining of the fabrics.

often is a consequence. Also, many of these souring agentspossess the disadvantage that they are diilicult to rinse from the fabric and their persistence causes'trouble in the fmther processing of. the goods, such for example, as in the subsequent starching, blu'ing, or sizing operations. The difliculties and troubles incident to the use of suchsou'ring agents as have been used in the past have been copiously discussed,

for example, in the Manual ofthe National Laundiym'ens Association. I

I have found that by a particular choice of agents, the alkaline and soap content of fabrics present after the cleansing step can be neutralized without incurring the diiliculties and disadvantages'incident to the use of such souring materials as have to my knowledge been used in the past. For this purpose I have found that simple neutral salts of weak bases and strong acids, capable of hydrolysis, especially in warm water, restricted to such simple salts as are colorless and water soluble, and further restricted to such simple salts whose positive radical will react to form colorless stearates,-

olea'tes, palmitates, or homologs occurring in soaps or other cleansing agents including phosphates. The metallic or positive radical of the simple neutral salt consists of such metal from groups II, III, or IV of the Periodic Table as will answer the above. requirements of forming colorless water soluble sulfates, nitrates, and halides, and colorless and preferably insoluble stearates a'hd oleates. The preferred metals from these groups are magnesium, zinc, and aluminum. 0f possible but less desirable usage 5 than 'these metals are beryllium, gallium, thallium, germanium, and tin. The negativecomponent of my' reagent may be derived from any of the strong mineral acids and may be a nitrate,

halide, or sulfate radical, for example. The mal0 .terials which I specifically prefer as my neutralizing agents are magnesium, zinc, and aluminum salts .of strong mineral acids? however, 1- appreciate, as above set forth, that numerous other materials may be used in place of these particu 1.1

lar materials withsiinilar or eomparable;'results. My reagents have the particular advantage that they are neutral, and therefore excesses of my reagent in'the fabric do not have deleterious eflects as do excesses of acid such as are en-. 20

- salts are used for souring. My reagents, which,

as stated, are capable. of hydrolysis, particularly in warm water, poses the characteristics of being stoichiometrically neutral when in solu- 30 tion, but inthe presence of alkaline materials, the strong acid radical of my reagent reacts to neutralize thealkaline materials, leaving the corresponding weak basic radical of my reagent to join with the negative radical associated with the alkaline or basic substance which it was sought to neutralize. In other words, the neutral salts, which I employ possess the'property of dissociating and reacting with alkaline constituents present just so far as is necessary to 40' neutralize the alkaline material present. When such alkaline material is neutralized, any excess of my reagent which remains is neutral and readily water soluble, so that it has n deleterlous effect on the fabric and is easily d The amount of my agent required to bring about the decomposition or neutralization of alkaline material or soap can readily be de termined by a rough titration of a sample of the water solution, which is in contact with the fabrics, with a standard acid or with a standard solution of one of my agents herein disclosed for the purpose of neutralization. Phenolphthalein will serve as a suitable indicator. agents may be added directly, a portion of a time, taking a sample of the liquid after the addition of each portion and adding a few drops of phenolphthalein thereto. If the indicator turns pink, more agent is required for neutralization. But when on test the indicator remains colorless, suflicient of my neutralizing agent has been added. After use of my agent for a time, being familiar with laundering operations, the approximate quantity of agent required will ordinarily be known in advance, thus minimizing the difilculty of the test or even eliminating the need for a test. If aluminum sulfate, for exampl is the agent employed, it may be roughtly stated that approximately pound of agent per hundred pounds of wash will normally be required; or about one teaspoonful of agent will be sufficient for the average household wash. However, as explained above, excesses of agent do not harm the fabrics, because of. the chemical neutrality of the agent, and are readily rinsable from the fabrics. The principal objection to the addition of a large excess of agent is the attendant unnecessary waste of agent.

In the appended claims the term alkaline material contemplates all laundering agents which give an alkaline reaction when in water solution, including the so-called neutral soaps.

What I claim is:

1. In the art of laundering fabrics which have been subjected to a washing operation with an aqueous solution of an alkaline cleansing agent, the method for neutralizing alkaline materials remaining in association with such fabrics subsequent to said washing operation which comprises bringing said fabrics into contact with a water solution of a simple neutral salt of a weak metallic base and a strong acid.

2. In the art of laundering fabrics which have been subjected to a washing operation with an aqueous solution of an alkaline cleansing agent, the method for neutralizing alkaline materials remaining .in association with such fabrics subsequent to said washing operation which comprises bringing said fabrics into contact with a water solution of a simple neutral salt whose positive radical is chosen from the metals of In lieu of titration, one or more of my groups II, III, or IV of the Periodic Table, which radical is capable of forming colorless and water soluble salts with the negative radical of a strong mineral acid and which forms colorless salts with radicals of fatty acids, and whose negative radical is taken from one of the strong mineral acids.

3. In the art of laundering fabrics which have been subjected to a washing operation with an aqueous solution of an alkaline cleansing agent, the method for neutralizing alkaline materials remaining in association with such fabrics subsequent to said washing operation which comprises bringing said fabrics into contact with a water solution of a simple neutral salt whose positive radical is chosen from the group of metals comprising aluminum, magnesium, zinc, cadmium, beryllium, gallium, thallium, germanium, and tin, and whose negative radical is chosen from a strong mineral acid to provide a colorless and water soluble salt.

4. In the art of laundering fabrics which have been subjected to a washing operation with an aqueous solution of an alkaline cleansing agent, the method for neutralizing alkaline materials remaining in association with such fabrics subsequent to said washing operation which comprises bringing said fabrics into contact with a water solution of a simple neutral salt whose positive radical is chosen from the group of metals comprising aluminum, magnesium,. and zinc, and whose negativeradical is chosen from among the strong mineral acids to provide a salt which is colorless and readily soluble in water.

5. In the art of laundering fabrics which have been subjected to a washing operation with an aqueous solutionof an alkaline cleansing agent, the method for neutralizing alkaline materials remaining in association with such fabrics subsequent to said washing operation which som prises bringing said fabrics into contact with an aqueous solution of a simple neutral salt whose positive radical is chosen from the group of metals comprising aluminum, magnesium, zinc, cadmium, beryllium, gallium, thallium, and germanium, and whose negative radical is chosen from a strong mineral acid to provide a color= less and water soluble salt.

6. In the art of laundering fabrics which have been subjected to a washing operation with an aqueous solution of an alkaline cleansing agent,

the method for neutralizing alkaline materials 

